Interface effect in sandwich like Ni/Ti₃C₂ catalysts on hydrogen storage performance of MgH₂

Sandwich like Ni/Ti₃C₂ catalysts with interfacial differences were controllably fabricated via modified wet chemical method. Through changing the solvents (water, ethylene glycol and an equal mixture of the two), Ni nanoparticles with different morphologies (size and dispersibility) on Ti₃C₂ matrix can be attained, leading to different interfaces between Ni nanoparticles and Ti₃C₂ matrix. After ball milling with MgH₂, the Ni/Ti₃C₂ catalyst prepared from the mixed solvent (Ni/Ti₃C₂-WE) shows the best catalytic activity, which exhibits the minimum Ni particle size and crystallite size, and the best dispersion of Ni nanoparticles on Ti₃C₂ matrix. The electronic interaction brought by the rich interfaces and contacts between Ni nanoparticles and Ti₃C₂ matrix can dramatically improve the hydrogen storage performance of MgH₂. In addition, electron transfers in multiple valence Ti (Ti⁰, Ti²⁺, Ti³⁺, Ti⁴⁺) and the unique structure of sandwich like Ni/Ti₃C₂ catalyst are also deemed as very crucial factors for enhancing catalytic activity of Ni/Ti₃C₂-WE. This research has shown the importance of the interfacial interaction between multiphase of catalysts on improving hydrogen storage performance of Mg-based materials experimentally and theoretically, providing a guideline to elaborate high efficiency multiphase catalysts.